Three Vehicles Introduction
The Buddha taught according to the capacities and potential of his disciples, at a level they could understand. Therefore, there were three main approaches, three Yanas or vehicles, composing the successive cycles of the Buddhist teachings.
the Shravakayana (vehicle of the Hearers);
the Pratyekabuddhayana (vehicle of the Solitary realizers);
the Bodhisattvayana (vehicle of the Mahayana).
However, these three vehicles are today more commonly known among Tibetan buddhists as the Hinayana or Theravada, the Mahayana or Great Vehicle, and the Vajrayana or Diamond Vehicle.
Each of these cycles of teachings became popular at different periods in the history of Buddhism.
Buddhism spread from India over time:
The Theravada teachings spread to Sri Lanka, the south of Thailand, Burma and Cambodia;
The Mahayana teachings spread to the northern countries of Pakistan, China, Vietnam, Japan and Korea;
All of the teachings including the Vajrayana spread mainly to Tibet as well as to Japan as a minor tradition.
In all schools of Buddhism, the mind is trained through the process of meditation. The core practice that cuts attachment to samsara -cyclic existence- is meditation on the impermanent nature of the world and of ourselves.
When, through the process of meditation and discipline, we have developed an understanding of the impermanence of all phenomena, the truth of suffering, the absence of ego and the emptiness of self and phenomena, then suffering naturally diminishes as the negative emotions fall away.
In the beginning we are concerned with the release of suffering for ourselves hence the teachings of the first yana.
With realization, compassion is generated naturally and concern for all sentient beings develops: we proceed on the Bodhisattva Path and develop the compassion necessary to cut away ego.
If we are very fortunate, we will find the Vajrayana path and accomplish full realization in one lifetime with the help of an authentic teacher who has already realized full enlightenment.